Newest transceivers from world leaders use our TWELP vocoder, providing highest quality and reliability of the voice communication

PRC 4090

 

AdaptiveDigitalVoiceTM

technology provides highest possible quality of the voice communication, adapting under fading noisy radio channel with variable SNR. The technology is based on our newest TWELP AMR Robust vocoder, operated on changable "on the fly" bit rate in range 3600 bps down to 300 bps and our newest Adaptive Voice Band modem.

 

TWELP Digital Voice in real conditions

Please watch this video up to end in order to hear a huge superiority of the Digital Voice with TWELP vocoder in comparison with analogue voice in channel with very low SNR. In practice, TWELP vocoder provides reliable clear voice communication in unworkable analoque channel.

 

  TWELP  vocoders provide highest speech quality, operating on twice lower bit rates  

 
A diagram demonstrates a huge superiority of the TWELP 2400 bps over MELPe 2400 bps and a closeness (and even superiority for a few languages) to GSM AMR 4750 bps vocoder of the speech quality in clear channel. Exact numbers are presented in the table below.
LanguageAMR 4750TWELP 2400MELPe 2400
American 3.351 3.330 3.077
Arabic 3.277 3.253 3.053
British 3.272 3.181 3.019
Chinese 3.267 3.307 2.970
Danish 3.311 3.275 3.022
Dutch 3.089 3.114 2.830
Finnich 3.166 3.049 2.791
French 3.277 3.325 3.106
German 3.321 3.183 2.998
Greek 3.206 3.275 3.004
Hindi 3.286 3.246 3.089
Hungarian 3.305 3.279 3.086
Italian 3.462 3.363 3.226
Japanese 3.369 3.407 3.188
Norwegian 3.267 3.286 3.032
Polish 3.263 3.267 3.029
Portuguese 3.377 3.350 3.146
Russian 3.186 3.165 2.952
Spanish 3.343 3.294 3.048
Swedish 3.391 3.269 3.147
Average3.2893.2613.041

Superiority of the TWELP 2400 bps vocoder over MELPe 2400 bps is on average 0.220 PESQ and just -0.028 PESQ in comparison with AMR 4750 bps

 

New highest level of speech quality in very noisy channel

 TWELP 4800 bps Robust vocoder

 TWELP 3600 bps Robust vocoder

 TWELP 2400 bps Robust vocoder

 
BER %MELPe 2400TWELP 2400 Robust (HD)TWELP 2400 Robust (SD)
0 3.041 3.127 3.127
1 2.513 3.039 3.079
2 2.186 2.963 3.006
3 1.940 2.810 2.964
4 1.748 2.582 2.908
5 1.582 2.321 2.842

You can play and listen short samples of the source speech as well as the speech processed by both vocoders in AWGN channel with BER = 5% for any of 20 languages, using links in the table below.

LanguageSource speechMELPe 2400 (BER = 5%)TWELP 2400 Robust (BER = 5%)
American
Arabic
British
Chinese
Danish
Dutch
Finnich
French
German
Greek
Hindi
Hungarian
Italian
Japanese
Norwegian
Polish
Portuguese
Russian
Spanish
Swedish

 

Our TWELP vocoders are used in the best transceivers from world leaders

4090

icom f8101

barret 4050

rapidm RA7 4050

 

TRC1193V

 

 

 Newest TWELP 700 bps vocoder is free of export restrictions and provides very high speech quality 

 
LanguageTWELP 700 bpsTWELP 600 bpsMELPe 600 bps
American 2.724 2.624 2.397
Arabic 2.603 2.479 2.254
British 2.678 2.577 2.414
Chinese 2.643 2.474 2.189
Danish 2.638 2.497 2.227
Dutch 2.475 2.366 2.173
Finnich 2.472 2.376 2.249
French 2.693 2.524 2.34
German 2.667 2.526 2.287
Greek 2.595 2.472 2.212
Hindi 2.660 2.563 2.403
Hungarian 2.659 2.546 2.359
Italian 2.837 2.720 2.428
Japanese 2.792 2.682 2.436
Norwegian 2.640 2.461 2.225
Polish 2.664 2.519 2.294
Portuguese 2.712 2.589 2.393
Russian 2.591 2.448 2.156
Spanish 2.648 2.537 2.389
Swedish 2.725 2.576 2.430
Average2.65582.52782.3128

Superiority of the TWELP 700 is on average 0.13(!) and 0.34 (!!!) PESQ appropriately